RE: ON-Demand supercharges

["Shubin, Pete" <pshubin@xxxxxxxxxxx>]

I did quite a bit of research into turbo chargers for the VW's I used to
have as a teenager.  I purchased a lot of parts and had a plan together
before the remaining money I wanted to use for the project went to the State
of California in the form of tuition and lots of the parts were sold for
similar reasons.  Then came grad school, then the kids...  You all know the
story.  It has been a long time since I really looked into this so forgive
the unavoidable mistakes.

I would argue that turbos could be set up to provide power "on demand" quite
easily by using an adjustable waste gate.  Turbos make power by using
exhaust gases to spin a turbine and pushing the fuel into the engine rather
than having the engine suck in the fuel air mixture.  You can change the
point at which the turbo kicks in by changing the relative size of the turbo
to the engine.  Use a big turbo and you'll get lots of boost high in the RPM
range.  Use a small turbo and you'll get less boost but it will kick in
sooner.  You can modify the amount of boost by using a valve that releases
pressure at a preset point.  They make adjustable waste gates that you can
adjust down to make the turbo generate very low boost pressures or no boost
pressure at all or you can set it to let the pressure build up (especially
at high RPM's) to gain more power but probably blow the engine up.  I
believe the waste gate was intended to protect the engine.  I was going to
use an adjustable waste gate and a smaller turbo with a high pressure
setting to get a wider rpm band of turbo usage with a strong top end and
adjust the waste gate to limit the pressure when I was just cruising.

I still have the turbo I was going to use in the garage with dream to
someday use it.  It was on the small size for a 2010 cc VW engine so I don't
think I could make it work on my 360 in the Scout.


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